1. Technical Field
This invention is directed towards low surface-energy surfaces, methods of producing low surface-energy surfaces on various substrates, and, formulations for treating surfaces to produce low surface-energy surfaces.
2. Background Art
Fluorinated hydrocarbons such as polytetrafluorethylenes have been used to form coatings on surfaces which resist acids and organic solvents. Liquid crystals have been used for electrooptical displays, passivating agents, doped oxides, protective films on metals, antistatic coatings and for other purposes as represented generally by the following patents. It is not believed that liquid crystal silanes in combination with fluoroalkyl silanes have been used to produce improved non-wettable or low surface-energy surfaces.
U.S. Pat. No. 4,730,904 to Pauluth et al discloses a group of organosilicon compounds which are said to have better, more uniform and more stable, homotropic orientation of liquid crystal on glass surfaces. These compounds are used for electrooptical display elements.
U.S. Pat. No. 4,277,525 to Nakayama et al disclose a silica-based liquid for coating glass. The liquid is obtained by the reaction of an alkoxysilane, a lower carboxylic acid and an alcohol, such as methanol, in the presence of an organic acid reaction accelerator. The coating are said to have excellent abrasion and chemical resistance and can be applied to glass plates as a passivating agent for providing passivation films on such surfaces, as a doped oxide on film on semiconductors, as protective films on metals, and as antistatic coating films on substrates.
U.S. Pat. No. 4,316,041 to Totten et al discloses certain liquid silanes, and more particularly certain alkoxy-, chloro-, and dimethyl amino silyl substituted compounds having liquid crystalline behavior, which can be chemically bonded to substrates, including glass, silica and other silicious materials, without the need for hermetic sealing. The chemical bonding of the silane to the substrate without the loss of its liquid crystal capability, is the primary objective of the invention.
U.S. Pat. No. 4,678,283 to Kreuzer et al discloses trialkanoyloxy silanes useful for generating a homeotropic orientation of liquid crystals on glass plate and ceramic surfaces used in visual electronic display elements.
U.S. Pat. No. 4,548,842 to Pohl discloses acylaminoorganosilicon compounds for treating glass surfaces to improve abrasion resistance, lubricity and durability to caustic wash compared to coatings containing organofunctionalsilane.
U.S. Pat. Nos. 4,388,453 and 4,358,391 to Finkelmann et al disclose crosslinked organopolysiloxanes having liquid crystal properties in which mesogenic molecules are chemically bonded to the organopolysiloxanes. The organopolysiloxanes are prepared from silanes or siloxanes containing mesogenic molecules which are crosslinked by addition or condensation reactions.
U.S. Pat. No. 3,803,050 to Haas et al discloses liquid crystal formulation which can be poured or sprayed onto a substrate, and, after evaporation of the solvent, a thin layer of liquid crystals is formed on the substrate. The substrate can be glass, ceramic or a variety of other materials.
U.S. Pat. No. 3,989,354 to Dubois et al discloses a nematic liquid crystal device having long-shaped molecules produced from hexamethyldisiloxane, and oriented perpendicular to electrodes plates for use in electrooptical displays.
Very few low surface energy treatments are available and those that are known all lack durability.